Ed Habtour works in the US Army Research Laboratory's Vehicle Technology Directorate, where he specializes in nonlinear dynamical systems.

US Army/Conrad Johnson

The US Army Research Laboratory and University of Minnesota have joined forces to develop extra pliable materials that can be 3D-printed on the battlefield and used to build robots that can move easily within confined spaces, the way biological organisms like a squid might maneuver through small holes in underwater rocks.

Current military robots can't move freely in highly populated environments because they're made with rigid mechanical parts.

However, that situation may change now that researchers have recently created a prototype of soft 3D-printed dielectric elastomer actuator -- an electroactive polymer that changes shape when hit with an electrical charge.

This 3D-printed actuator can make extreme bending motions, which means it could be used to fit through spaces humans can't maneuver.

The researchers explain their findings in detail in a paper published this month in Extreme Mechanics Letters via the Science Direct journal.

More robots

The researchers also want to design these flexible robots to be self-aware, self-sensing and capable of adjusting their own shapes to adapt to different external and internal conditions, according to Ed Habtour, an ARL researcher who specializes in nonlinear structural dynamics.

This isn't the first time we've seen bio-inspired robots. In 2016, for example, Harvard researchers build a tentacled soft robot called Octobot made entirely of flexible parts and inspired by real-life octopi.

The tiny robot's squishy-looking tentacles move via a specific chemical reaction that turns hydrogen peroxide into gas that flows into Octobot's arms, inflating them like a balloon.

Also in 2016, another team of researchers at Case Western Reserve University created a robot made from the muscle of a sea slug in a flexible 3D-printed polymer body. Robots such as these could be used in surveillance and search missions in the ocean.

In 2015, NASA began studying the use of a soft, tentacled robots that could some day explore watery moons like Jupiter's Europa.